# Two and three photon excited luminescence of single gold nanoparticles: Switching between plasmon- and electron-hole-pair emission by ultrashort laser pulses

## TL;DR

This study investigates how ultrashort laser pulses induce two- and three-photon luminescence in single gold nanoparticles, revealing a switch between plasmon and electron-hole pair emission based on pulse duration.

## Contribution

It provides a quantitative model describing the multiphoton luminescence mechanisms in gold nanoparticles, highlighting the influence of pulse duration on emission pathways.

## Key findings

- Two- and three-photon emission dominated by electron-hole pairs with 100 fs pulses.
- Emission caused by plasmon decay with 500 fs pulses.
- Model explains interplay between plasmon and electron-hole emission in nanorods.

## Abstract

In this work we use femtosecond laser pulses of 800 nm wavelength to excite and characterize the multiphoton luminescence emission of single gold nanoparticles. For excitation with 100 fs laser pulses we observe a two and three photon emission dominated by radiative electron hole pair recombination, while the emission is caused by radiative plasmon decay for excitation with 500 fs pulses. For single gold nanorods with different aspect ratios, we study the interplay between the particle plasmon and electron hole pairs, which enables us to develop a quantitative model to fully describe the two and three photon luminescence emission of single gold nanoparticles.

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Source: https://tomesphere.com/paper/1812.01409